Neuropeptides Flashcards
How are neuropeptides synthesized?
Translation of preprohormones on the rough ER (when the signal peptide is cleaved off, it´s called a prohormone), then the prohormone is tranported in dense core vesicles budded off the Golgi through the axon (app. 2 days). On this axonal transport neuropeptides are synthesized from the prohormone
Which posttranscriptional modifications are made on the neuropeptides in the vesicles during the axonal transport?
pyruGlu and amide groups to protect against enzymatic degration
How is the neuropeptides protected against enzymatic degradation?
The pyroGlu is cyclised glu, which are more stabile than linear. The amide is protecting against degradation by carboxylase in the blood
What are oxytocin involved in?
Empathy and social behavior: love, all aspects of reproducion
What are vasopression involved in?
Blood pressure, water absorption in kidney and pair bonding
From where are oxytocin and vasopressin secreted when acting as a hormone?
From the hypothalamus to the posterior pituitary
Explain the cortisol pathway adapting to stress.
Activated at long-term stress: CHR released from hypothalamus stimulates the secretion of ACTH from the anterior pituitary. ACTH then stimulates the secretion of cortisol from the arenal cortex. Cortisol mobilizes glucose and lipids and stops inflammatory pathways. Negative feedback loop.
Explain the thyroid system.
TRH released from hypothalamus stimulates the secretion of TSH in the anterior pituitary. TSH stimulates the secretion of T3/T4 from the thyroid gland. T3/T4 stimulate basic metabolic processes, temp., heart rate and growth of thyroid gland. Negative feedback loop.
What is the consequnce of too littel iodine in the diet?
Too littel T3/T4 causes weak feedback, which results in a high TSH concentration leading to excessive growth of the thyroid glands (=goiter disease)
What are the reason and symptoms of Cusching´s syndrom?
Abnormally high cortisol concentration. Moon face.
Which opium receptors do you know, and are they GPCRs or ion channels?
3 GPCRs (Gi), my, kappa and delta
How is the opium receptors involved in pain?
They are interneurons, and reduce transmission of nociceptor impulses in the dorsal root ganglion
