Toxicants Affecting the Respiratory System (15)

Question 1

What is reproductive toxicity?

Answer 1

refers to any manifestation of xenobiotic exposure reflecting adverse effects on the physiological processes and associated behaviors

and/or anatomical structures involved in animal reproduction or development

Question 2

What is developmental toxicity?

Answer 2

refers to any adverse effect on the developing organism
associated with either pre-conception parental exposures to
toxicants or post-conception xenobiotic exposures to the
embryo, fetus or pre-pubertal offspring

Question 3

What is teratogenesis?

Answer 3

refers specifically to developmental defects induced by toxicant exposures occurring between conception and birth

DART

Question 4

What are some mechanisms in which toxicants cause reproductive harm?

Answer 4

• toxicant-induced cellular dysregulation
• alterations in cellular maintenance
• endocrine disruption

Question 5

What are endocrine disruptors?

Answer 5

effects which are mediated directly by interactions between the xenobiotic and an endogenous hormone receptor

Question 6

What are some endocrine disruptors?

Answer 6

bisphenol A (plastics)
phytoestrogens

Question 8

What are the toxicants in Subterranean clover, Red clover, White clover? What does it do?

Answer 8

Phytoestrogens or isoflavones (formononetin, biochanin A, genistein)

Question 9

What do formononetin, biochanin A, genistein do?

Answer 9

molecules ingested and metabolized into shape mimicking estrogen

Question 10

What is the toxicant in alfalfa?

Answer 10

coumestrol

Question 11

What is clover disease?

Answer 11

sheep associated with the consumption of the isoflavones in clover, resulting in infertility associated with abnormal estrous cycles and structural and functional changes in the cervix

alterations of cervical mucus

Question 12

Which molecule is structurally similar to estradiol?

Answer 12

genistein

Question 13

What are the effects of genistein?

Answer 13

can induce structural changes and possibly irreversible organizational abnormalities in the cervix and uterus of exposed gilts

Question 14

What is coumestan exposure associated with in cattle?

Answer 14

associated with various and, sometimes, seemingly conflicting
clinical presentations (e.g., hyperestrogenism, nymphomania, swelling of the external genitalia, estrus suppression, inhibition of ovulation and cystic ovarian disease)

Question 16

What can slaframine cause?

Answer 16

marked drop in milk production in dairy cattle

Question 17

What is the toxicant in locoweed?

Answer 17

swainsonine

Question 18

What does swainsonine cause - reproductively?

Answer 18

decreased fertility in cattle characterized by decreased conception rates and lower calving percentages

Question 19

What is the toxicant in Fusarium roseum (a fungus)?

Answer 19

zearalenone

Question 20

What toxicants can zearalenone be associated with?

Answer 20

vomitoxin

deoxynivalenol (DON)

Question 21

Who is most affected by zearalenone toxicity?

Answer 21

pre-pubertal gilts

Question 22

Why are pigs more susceptible to zearalenone toxicity?

Answer 22

most likely related to the slow metabolism and enhanced enterohepatic recirculation of zearalenone

Question 23

What is the toxin in tall fescue grass?

Answer 23

ergovaline - from the endophyte Neotyphodium coenophialum

Question 24

What does fescue toxicosis cause reproductively in horses?

Answer 24

blocks signals of parturition (dopamine) = no udder develop, foals keep growing

Question 25

What does fescue toxicosis cause reproductively in cattle?

Answer 25

epidermic hyperthermia, “summer syndrome”

Question 26

How do you treat fescue toxicosis?

Answer 26

domperidone (promotes mammary development) - on the downside may result in early leakage and lost of colostrum

Question 27

When does fescue toxicosis reproductively do the most harm?

Answer 27

last three months of gestation

Question 28

What is the toxicant in cottonseed?

Answer 28

gossypol

Question 29

What does gossypol cause reproductively?

Answer 29

exposure of peri-pubertal or sexually mature males to sufficient dosages of free gossypol adversely
affects the seminiferous epithelium and disrupts normal spermiogenesis

Question 30

What is the toxicant of pine (ponderosa)?

Answer 30

isocupressic acid

Question 31

What are the causes and effects of pine (ponderosa)?

Answer 31

Ingestion of cattle of pine needles containing isocupressic acid results in late-term abortion with retained placenta

Interferes with Ca2+ → changes in vasoconstriction

Question 32

Review jervanine alkaloids

Answer 32

involves interference with the sonic hedgehog (SHH) signal transduction pathway and the inhibition of neuroepithelial cell mitosis

Question 33

Review lupine, poison hemlock, etc effects

Answer 33

Crooked Calf Disease