University:
York University
Course:
SC/BIOL 4320 | Vertebrate Endocrinology
Academic year:

2023
Views:

356

Pages:

4
Author:

Niklas

9 Meschoon I Structure Diverse Role of Nonapeptides A General types of nenapeptides- vertebrates Tocin-like Neutral peptide-no (+) or (-) charge Leu or lle (neutral amina acids). 2 Pressin-like Basic peptides net() chargt example Hybrid has biological activities of focin preste Arg or Lys Arginin Nasspressin, lysine vasopressin, phenspressio B Chemical Structure consist of 4 amino acids Cys For amino acid 1.6 Essential to be a tocin disulfide band between 1-6 Cya (1) Tyr (2) lle (3) Oxytocin Cys (6) Asp (5) Gin(4) Pro (7) Leu (8) Gly-NH2 (9) Neutral AA Essential for activity forms a loop for 1-6 -amino acid 7-9 forms a "tail" A.A 8 has to be neutral (Lev. lle) -essential for activity A.A. has to be lle -essential to be a "lacin" Cys- facins AA3 lle A. A neutral (Leu. The) Pressin Ph AA3 Phe AA, basie (Lys. Arg) Essential to be s pressin Cys ( 1)-Tyr ( 2)-Phe (3) Cys (6) Asp (5) - Gin (4) Pro (7) Arg (8) Gly-NH2 (9) Basic AA Essential for activity Arginine Vasopressin Cys for amino acid 1.6 disulfide band belween 1-6 farms a loop for 1- amino acid 7-9 forms a "tail" A.A. has to be basic (Arg, Lys). required for biologic activity A.A. 3 has to be a phenylalanine (Phe) essential for prestin Alternative Pressin Cys (1)-Tyr (2) Phe (3) Cys (6)-Asp (5) Gin(4) Pro (7) Lys(8) Gly-NH2 (9) Lysine Vasopressin Lys is AAB, not Arg- su Fressm Pigs Hippes Neurohormone (releasing hormone) Neurohormone D. Nonapeptides as neurohormones- Secreted throughout body 1. Oxytocin ↑ reproductive smooth muscle -birth, ejaculation, orgasm Tmilk let down myoepithelial cells of mammary gland 2. Arginine Vasopressin stimulate vascular smooth muscle contraction ↑ water reabsorption antidiurelic hormone payslogical) -opens water channels aquaporin retains more water OXY/AVP (SON/PVN) Median Eminence Neurohormone (releasing hormone) Pars Nervosa Neurotransmitter Neurohormone this section ↑ blood pressure (pharmacological) AVP Action -alcohol AVP -dehydration headache Comerting duel wlo AVP you cannot successfully reabsorb water back into body PKA will translocate aquaporins la cait surface, water wit thier wis rattecting duct much faster Кан D. Nonapeptides as neuromodulators Secreted into specific region in brain. 1. Pair band formation PRA will also stimulate transcription of aquaparin proteins Prairie Vole, Menetias regeater Monogamous Similarty to humans. Distribution of OXY Receptors monogamous frarie vale -nonmonogamous Meadow vole Addiction Reward meadow vole окул Median Eminence. OXY/AVP (SON/PVN) Fars Nervosa Neurohermone (releasing hormone) Neurohormone this section D Nonapeptides as neuromodulators 2 Other Effects a. oxytocin-female oriented → in rals, mice, hamsters female mating behavior Ewes to nuture young instilts maternal, benaviors b. AVP-male sente ↑ paternal behavior Taggression toward strange males *The behavioral effects of OXY+AVP are due to their roles as NT or NM NOT NH The Pineal Gland A. Anatomy Forebrain-Anterior brain telencephalon anterior diencephalon-posterior 2. Diencephalon Center → Thalamus Epiphysis or Pineal Floor 2 cen types ① Roof → Epithalamus pinral penial epiphysis Secretes melatonin Pinealocytes Neuroglial col suppark Secretion pattern of melatonin Photoperiod Photophase = light Scotophase dark Plasma Melatonin Levels Fig4-37 W. Scotophase