GnRH is a ?

Ans. is 'a' i.e., PeptideThree general classes of hormone exist : ?1) Proteins and polvpeptide The peptide/protein hormones are:i) Hypothalamus :- Thyrotropin releasing hormone (TRH), coicotropin-releasing hormone (CRH), Growth-hormone releasing hormone (GHRh), Growth hormone inhibitory hormone (GHIn), i.e., somatostatin, Gonadotropin-releasing hormone (GnRH).ii) Anterior pituitary :- Growth hormone, thyroid stimulating hormone (THS) or thyrotropin, adrenocoicotropin hormone (ACTH), prolactin, follicle stimulating hormone (FSH), leutinizing hormone (LH).iii) Posterior pituitary :- Antidiuretic hormone (ADH)/vasopressin, oxytocin.iv) Thyroid gland :- Calcitoninv) Pancreas :- Insulin, glucagon.vi) Parathyroid :- Parathormonevii) Placenta :- Human chorionic gonadotropin (HCG), Human somatomammotropin.viii) Kidney :- Renin, erythropoietinix) Hea :- Atrial natriuretic peptide (ANP)x) Stomach :- Gastrinxi) Small intestine :- Secretin, Cholecystokinin (CCK)xii) Adipocytes LeptinSome of these peptide hormones are glycoproteins, i.e., they have sugar associated with proteins. Glycoprotein hormones are FSH, LH, TSH, human chorionic gonadotropin, erythropoietin.2) Steroid hormones Steroid hormones are : ?i) Adrenal coex :- Coisol (Glucocoicoids), Aldosterone (mineralocoicoids).ii) Gonads :- Testosterone, estrogen, progesterone.iii) Kidney :- 1, 25 - Dihydroxycholecalciferol3) Amine hormones These hormones are derivatives of amino acid tyrosine. These hormones are : ?i) Thyroid gland :- Thyroxine (T4) and Triiodothyronine (T3).ii) Adrenal medulla :- Norepinephrine (Noradrenaline), Epinephrine (adrenaline)iii) Hypothalamus :- Dopamine or Prolactin inhibiting factor (PIF).