endocrine 1 Flashcards
role of hormones
integration and contol body functions in close co operation with nervous system
hormone definition
a chemical substance produced in one part of the body that diffuses or transported to another area where it influences activity and tends to integrate component parts of the organ
three chemical classes of hormones
amine, peptide, protein, glycoprotein
steroids
unsaturated fatty acids
two types of hormones
membrane active hormones
gene active hormones
where would you find membrane active hormones
on the surface of cells
where would you find gene active hormones
in the cytoplasm
on the cell nuclear chromatin
principles of hormone therapy
mode of application size of dose physiological level overdose,, permanent large doses overlapping effect incr efficacy decr efficacy
examples for overlapping effect
- gluco and mineralocorticoids
- oxytocin-vasopressin
- FSH-LH or eCG/PMSG-hCG
examples for increased efficacy
- synthetic analogues
- esterification, complex formation
- enhanced synthesis
examples for decreased efficacy
- antagonists
- anti-hormone
- inhibitors of hormone synthesis
classifications of hormones
releasing and inhibitory hormones hormones of pituitary gland thyroid gland endocrine pancreas sex steroid hormones and anabolic agents corticosteroids pineal gland
where are releasing and inhibitory hormones produced
hypothalamus, transported via the hypophyseal portal system into the adenohypophysis
name releasing and inhibiting hormones
GnRH TRH CRH GRH GIH PRH PIH
GnRH
gonadotropin releasing hormone, anterior pituitary -> releases LH and FSH -> ovary, testis
TRH
thyrotropin releasing hormone, AP-> releases TSH -> thyroid gland
CRH
corticotropin releasing hormone, AP -> releases ACTH -> adrenal cortex
GRH
somatotropin releasing hormone, AP-> releases GH -> tissues
GIH
somatotropin inhibitory hormone, AP-> releases GH -> tissues
PRH
prolactin releasing hormone, AP-> releases prolactin -> mammary gland
PIH
prolactin inhibitory hormone, AP->inhibits prolactin output
hormones of the adenohypophysis
STH ACTH TSH prolactin FSH LH hCG PMSG eCG
STH
somatotropin, growth hormone, general soma -> IGF 1
ACTH
adrenocorticotropic hormone, adrenal cortex -> aldosterone, deoxycorticosterone, cortisol
TSH
thyrotropic hormone, thyroid gland -> thyroxine
name two gonadotropins
FSH and LH
hCG
human chorionic gonadotropin, predominantly LH like activity
PMSG, eCG
pregnant mares serum gonadotropin, mainly FSH like activity, but LH like activity too
hormones of neurohypophysis
ADH
oxytocin
ADH
antidiuretic hormone, vasopressin, renal tubules
oxytocin
uterine myometrium and mammary myoepithelium
hormones of thyroid gland
T3, T4
hormones of endocrine pancreas
insulin
glucagon
sex steroid hormones and anabolic agents
oestrogens
progesterone and progestagens
androgens
corticosteroids
mineralocorticoids
glucocorticoids
hormones of pineal gland
melatonin
somatotropin is produced by which cell type
somatotroph
somatotroph hypothalamic stimulating factors
GHRH, Ghrelin
somatotroph hypothalamic inhibitory factors
somatostatin
somatotroph main target organs
liver, skeletal structure
somatotroph hormones of the target organs
insulin like growth factor
prolactin pituitary cells
lactotroph
lactotroph hypothalamic stimulating factors
TRH
lactotroph hypothalamic inhibitory factors
dopamine
lactotroph main target hormones
mammary gland
lactotroph hormones of target organs
not produced
LH and FSH pituitary cells
gonadotroph
gonadotroph hypothalamic stimulating factors
GnRH
gonadotroph hypothalamic inhibitory factors
GnIH
gonadotropin main target organs
gonads, ovaries and testes
TSH pituitary cells
thyrotroph
thyrotroph hypothalamic stimulating factors
TRH
thyrotroph hypothalamic inhibitory factors
somatostatin
thyrotroph main target organs
thyroid gland
ACTH pituitary cells
corticotroph
corticotroph hypothalamic stimulating factors
CRH
corticotroph hypothalamic inhibitory factors
unknown
corticotroph main target organs
adrenal cortex
can somatotropin be given orally
no, it is ineffective
what hormones control the release of GH
GHRH
GHIH
release of GH is also controlled by
ghrelin polypeptide
plasma level of GH
source of ghrelin polypeptide
predominant source GI, hypothalamus, smaller amounts in placenta, kidney and pituitary gland
causes for increase of plasma GH level
during sleep and by hypoglycaemia, exercise, stress, alpha adrenoceptor agonists, dopamine
causes for decrease of plasma GH level
hyperglycaemia, glucocorticoids, beta adrenoceptor agonists
what happens in the absence of IGF1
laron dwarfism, treatment with recombinant IGF1 mecasermin
effects of GH
direct and partly indirect
basically anabolic action
stimulates growth
controls metabolism of carbohydrates, proteins and fat
promotes N retention, transport of AAs into tissues incr and accelerates their incorporation into proteins
what happens in disordered GH production
giant
acromegaly
dwarfism, defiency
how do we diagnose disordered GH production
stimulation test
what drugs are used for stimulation test for disordered GH production diagnosis
clonidin
xylazine
sermirelin
GH use
growth promoter - to incr milk production, meat quality
replacement therapy
Gh responsive alopeia in dog
what can happen in overproduction of GH
acromegaly or gigantism
how do we inhibit GH production
synthetic somatostatin analogues
D2 dopaminergic agents - presynaptic, feedback
pegvisomant - GH receptor, inhibition of IGF1 synthesis
corticotropin effect
incr synthesis of enzymes involved in steroid biosynthesis
incr in conversion of cholesterol to pregnonlone
incr level of cortisol and corticosterone
corticotropin use
incr glucocorticoid level in conditions where it is relatively or absolutely low
cattle ketosis
restore function of adrenal cortex
stimulatio test/ differential diagnosis of adrenocortical hypo/hyperplasia
how do we give natural ACTH with porcine origin IM
depot preparations avaliable
disadvantages of natural ACTH of porcine origin
short half life
immunogenity
orally ineffective
CRH products avaliable
synthetic human and ovine corticotropin releasing hormone
when do we use CRH
CRH stimulation test
thyrotropin makeup
glycoprotein consists of two chains
can you get bovine thyrotropin nowadays
no, only in the past, recombinant human TSH has replaced the bovine products in human clinical use
thyrotropin effect
it increases iodine uptake by the thyroid gland and the production and secretion of thyroid hormones
use of thyrotropin
in research
treatment of acanthosis nigricans
to diagnose primary hypothyroidism TSH or biosynthetic
ADH makeup
9 AAs, slight interspecies differences in AAs combo
main function of ADH
control of water balance
three types of ADH receptors
V1a, V1b and V2
where is v1a receptor
on vascular smooth muscle cells -> vasoconstriction
where is v1b receptor
anterior pituitary stimulation of ACTh
where is V2 receptor
on the renal tubules -> incr water permeability and water reabsorption in the collecting ducts by insertion of aquaporin 2 channels
use of ADH
diagnosis and treatment of total and partial central diabetes insipidus, seperation from diabetes melitus
preparations of ADH
natural vasopressin nasal spray
synthetic analogue desmopressin, injectable oral and nasal spray dosage forms are avaliable
chlorpropamide
in DI thiazide diuretics may be used, paradoxical action
what do we call overproduction of ADH
SIADH - syndrome of inappropriate ADH
ADH receptor antagonists
conivaptan
tolvaptan
lixivaptan
non specific drugs for use in SIADH
demeclocycline, tetracyclines, lithium, antidepressants
conivaptan hwo do we use
only for iv use
conivaptan selectivitity
less, also V1
tolvaptan and lixivaptan seletivity
V2 receptor antagonists, po application also avaliable
whats type 1 diabetes
insulin dependant diabetes melitus
whats type 2 diabetes
non insulin dependant diabetes melitus
insulin makeup
two amino acid chains, linked by disulphide bridges, small interspecies differences in AAs sequences
which cells produce insuli
pancreatic Beta cells
insulin biosynthesis
preproinsulin in ER -> proinsulin -> transportation to golgi complex -> insulin -> storage in secretatory granules in complex with zinc
how is insulin excreted
exocytosis
how is insulin secretion regulated
mainly by glucose
actions of insulin
incr intracellular uptake of glucose, AAs, FA, K+
in the cells incr glucose metabolism, protein synthesis, deposition of fat and glucose
results of lack of insulin
glucose intolerance, hyperglycaemia, glucosuria
polyruai polydypsea, saluresis
weight loss
incomplete fat metabolism -> incr plasma free FAs -> ketoacidosis -> coma
metabolism of insulin
relatively specific insulin degrading enzyme is rapid
use of insulin
to treat diabetes melitus
ketosis and fatty liver in cattle which are non responsive to glucose of GC therapy alone
how do we classify insulin products
origin
purity
formulation - regular, insulin zinc suspension
origin of insulin products
natural - bovine or ovine
biosynthetic gene transfer
regular formulation insulin
rapid onset, duration of action generally short, depends on route of administration -IV,SC
insulin zinc suspension caninsulin
higher Zn content + acetate buffer + suspension, amorphous intermediate duration, crystalline more prolonged
protamine zinc insulin
suspension of insulin + protamine sulphate + zinc chloride in buffered water
-duration 24-36hrs
isophane insulin
- suspension of Zn insulin crystals and protamine Zn in buffered water
- cloudy or milky suspension
- duration 12-30hrs
surfen insulin
long activity, aminoquinuride surfectant
insulin dosage
individual
adverse effects of insulin
acute hypoglycaemia - excessive insulin dose or inadequate food intake
somogyi rebound effect - hypoglycaemia induced hyperglycaemia
allergic reaction, antibody formation
insulin interactions with drugs that decr hypoglycaemic activity
GCs, dobutamine, oestrogen/progesterone, xylazine, thiazide diuretics
insulin interactions iwth drugs that incr hypoglycaemic activity
anabolic steroids, beta-adrenerg blockers, MAO inhibitors, phenylbutazone, salicylates
in which type of diabetes do we use orally active hypoglycaemic drugs
type 2 non insulin dependant diabetes
name orally active hypoglycaemic drugs
sulphonylurea substances glinides biguanides thiazolidine diones acarbose
sulphonylurea substances
tolbutamide - short action, cardio effect chlorpropamide - long acting metahexamide glibenclamide gliclazide glipizide
glipizide dose for cat
5mg/cat
sulphonylurea substances actions
release of insulin incr sensitivity of the cells to insulin incr number of receptors incr the binding of insulin to plasma proteins decr glucagon incr
sulphonylurea substances side effects
liver toxicity, elevated CYP enzyme activity
glinides effect
incr insulin secretion
name a glinide
nateglinide
name biguanides
fenformine
buformine
methofromine
biguanides action
stimulation of the action of insulin, decr oral absorption of glucose
thiazolidine diones effects
veterinary experiences are not avaliable, modulation of insulin dependant genes, reduction of blood sugar level
acarbose effects
inhibition of alpha glycosidase activity in GI, less rapid elevation of blood sugar level after food consumption, also with insulin in dogs and cats
hormones of the thyroid gland
calcitonin
L thyroxine
L tri iodthyronine
effect of calcitonin
control of hypercalcaemia
role of L thyroxine and L tri iodothyronine
TRH-TSH control - production, storage, release
where would you find T3 and T4
mainly intracellularly
in plasma TBG - low non bounded fraction
how are T3 and T4 excreted
mainly by faeces
functions of T3 and T4
control of metabolic rate of all tissues, in conjugation with other hormones, they are necessary for normal differentiation, dvelopment and function of nervous, repro and musculo-skeletal system
thyroid hormones effect on calorigeesis, thermo regulation
basal metabolic rate and O2 consumption
thyroid hormones effect on growth and maturation
normal CNS development
thyroid hormones effect on carb metabolism
glycogenolysis incr
glycolysis incr
anti insulin
thyroid hormones effect on protein metabolism
synthesis and degradation incr
thyroid hormones effect on cardiovascular system
myosin ATPase incr
beta-receptor numbers incr
thyroid hormones effect on dermatology
normal hairs, fatty acids turnover in skin, normal keratin turnover
thyroid hormones effect on neuromuscular
normal myelin production
thyroid hormones effect on repro
maintainence of normal protein synthetic rates
thyroid hormones effect on endocrine
normal secretion of GH, gonadotropins, cortisol but prolactin decr
thyroid hormones immunologic
stimulation
causes for hypothyroidism
a defiency of iodine, feeding cabbage
malfunction of thyroid gland itself
deficient output of TSH from pituitary gland
alimentary hypothyroidism cause
defiency of iodine, feeding cabbage in ruminants
primary hypothyroidism cause
malfunction of the thyroid gland itself
secondary hypothyroidism cause
deficient output of TSH from the pituitary gland
in which species do we get hyperthyroidism
may happen in dogs, but moreso in cats
types of preparations for hypothyroidism
crude thyroid products
synthetic preparations
name some synthetic preparations
L thyroxine/levothyroxine
L thyroxine Na
L tri iodothyronine
L thyroxine/levothyroxine which species
dog, cat, horse - sid, bid or po
which species do we use L thyroxine Na
dog iv or sc
in which species do we use L tri iodothyronine
dog, tid, po
preparations for hyperthyroidism
iodine
thiouracils
I131 isotope
name the thiouracils
thiouracil
propylthiouracil
thiamazole
carbamazole
mineralocorticoids production
renin angiotensin ACTH stimulate
mineralocorticoids physiological role
incr Na reabsorption, water retention, blood-pressure, inflammatory processes
preparations for treatment of hypoadrenocorticism
aldosterone
desoxycorticosterone pivalate
desoxycorticosterone acetate
fludrocortisone acetate
side effects of preparations for treatment of hypoadrenocorticism
hypokalaemia, hypernatraemia, water retention, muscle weakness, hypertension, incr susceptibility to infection
aldosterone for hypoadrenocorticism
only avaliable for research
how is fludrocortisone used
oral use, slight GC side effect
preparations for hyperadrenocorticism
pituitary dependant cushings syndrome
pituitary or adrenal dependant cushings syndrome
pituitary dependant cushings syndrome aim
inhibition of ACTH synthesis and release
pituitary dependant cushings syndrome name
bromocriptine
pergolid
cyproheptadine-Hcl - unproved
preparations for pituitary or adrenal dependant cushings syndrome
ketocunazole
mitotane
trilostane
