beyond the classic endocrine glands Flashcards
(34 cards)
2 functions of lipoprotein lipase (LPL)
triglyceride hydrolysis (lipolysis), involved in receptor mediated lipoprotein uptake
What hormones mean that fat can act as an endocrine gland
leptin (signal satiety) adiponectin (increases insulin sensitivity) resistin cytokines androgens oestrogens
What do mutations of the leptin gene [LEP] in adipose tissue/leptin receptor gene [LEPR] in hypothalamus lead to?
abnormal eating behaviour, development of early onset morbid obesity
leptin deficiency treatment
leptin - results in reduction in fat mass
why is leptin treatment only rarely effective
LEP mutations are rare
what disease is associated with leptin resistance
obesity - leptin levels are already high in obesity
what happens with leptin/adiponectin/resistin in healthy adipose tissue
leptin signals satiety to the brain
adiponectin increases insulin sensitivity
resistin levels low
what happens with leptin/adiponectin/resistin in adipose tissue in obesity
leptin secretion high, but there’s resistance to leptin
adiponectin secretion low
insulin resistance, diabetes, and metabolic syndrome
what is disturbed in obesity
normal balance of cytokines (IL-6, TNF-alpha)
what is metabolic syndrome
general disorder of energy metabolism associated with obesity (Esp visceral) hypertension, raised serum glucose, high serum TGs, insulin resistance
what is the largest endocrine gland in the body
gastroenteropancreatic tract
what does gastrin do
stimulates gastric acid secretion and proliferation of gastric epithelium
what stimulates gastrin release
presence of peptides and AAs in the gastric lumen
what does cholecystokinin
stimulates secretion of pancreatic enzymes, and contraction/emptying of gall bladder
what stimulates release of cholecystokinin
presence of FAs and AAs in the small intestine
what does secretin do
stimulates secretion of water and bicarbonate from pancreas and bile ducts
what stimulates release of secretin
acidic pH in lumen of small intestine
what does ghrelin do
stimulant for appetite and feeding also stimulates secretion of GH
what stimulates release of ghrelin
not clear, but secretion peaks before feeding and diminished with gastric filling
what does motilin do
stimulates housekeeping patterns of motility in stomach and small intestine
what stimulates motilin release
not clear, but secretion is associated with fasting
what does gastric inhibitory polypeptide do
inhibits gastric secretion, motility
potentiates release of insulin from beta cells in response to elevated blood glucose concentration
what stimulates release of gastric inhibitory polypeptide
presence of fat and glucose in small intestine
Which three different tissues act on the hypothalamus to regulate food intake
GI TRACT - secretes hormones
BRAIN - vagal afferents to the nucleus of the tractus solitarius
ADIPOSE - secretes leptin
