Abstract
The role of adrenergic receptors in nicotine-induced hyperglycaemia has not been well studied in amphibians. Thus, this study investigates the effects of alpha and beta adrenergic receptor blockers in nicotine-induced hyperglycaemia in the common African toad Bufo regularis. Toads fasted for 24 h were anaesthetized with sodium pentobarbitone (3 mg/100 g body weight) intraperitoneally (i.p) and given intravenous (i.v) injection of 0.7% amphibian saline, or nicotine (50 µg/kg), nicotine(50 µg/kg i.v) 30 min after pretreatment with prazosin (0.2 mg/kg i.v), propranolol (0.5 mg/kg i.v) or combination of both prazosin (0.2 mg/kg i.v) and propranolol (0.5 mg/kg, i.v). Thereafter, blood samples were also collected from truncus arteriosus for estimation of blood glucose level using the modified glucose oxidase method. Nicotine caused significant increase (P<0.01) in the levels of blood glucose in the common African toad. Pre-treatment of the toads with prazosin (0.2 mg/kg i.v) or propranolol (0.5 mg/kg, i.v) significantly (p < 0.01) reduced the hyperglycaemia induced by nicotine (50 µg/kg i.v). However, the combination of prazosin (0.2 mg/kg i.v) and propranolol (0.5 mg/kg, i.v) abolished the hyperglycaemic effect of nicotine (50 µg/kg i.v). The above results on glucose metabolism suggests involvement of both alpha and beta adrenoceptors in nicotine-induced hyperglycaemia in common African toad B. regularis. Key words: Nicotine, hyperglycaemia, prazosin, propranolol, common African toad Bufo regularis.
Highlights
The main psychoactive and addictive compound in tobacco (Benowitz, 1988), is a low molecular weight alkaloid found in cigarettes and through insecticide inhalation (Hosseini, 2011)
6) while w propran nolol pre-trea atment abolished the incre easess in glucose levels cause ed by nicotine e injection
5 The effects off nicotine (50 μg g/kg) on blood glucose g levels in n untreated and d in toads treated with both prazzosin
Summary
The main psychoactive and addictive compound in tobacco (Benowitz, 1988), is a low molecular weight alkaloid found in cigarettes and through insecticide inhalation (Hosseini, 2011). Nicotine rapidly increases blood sugar levels by mobilizing glucose release from hepatic and muscle glycogen stores through adrenergic actions (Molimard, 2013). Our study aimed at investigating the role of the alpha and beta adrenergic receptors in nicotine-induced hyperglycaemia in the common African toad (Bufo regularis).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
