THE ROLE OF ALPHA AND BETA ADRENERGIC RECEPTORS IN CORTISOL-INDUCED HYPERGLYCAEMIA IN THE COMMON AFRICAN TOAD (BUFO REGULARIS)

Dr Olaniyan Olugbemi Tope and Isehunwa, G. O.1*, Olaniyan, O. T.2 and Alada, A. R. A   (Published 2019)

Dr Olugbemi Tope
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Abstract

The role of adrenergic receptors in cortisol-induced hyperglycaemia is not well known. The present
study investigates the effects of adrenergic receptor blockers in cortisol-induced hyperglycaemia in the
common African toad (Bufo regularis). Each toad was fasted and anesthetized with sodium
pentobarbitone (3 mg/100 g i.p). The animals (control) received intravenous (i.v) injection of 0.7%
amphibian saline while animals (untreated) were given cortisol (20 ?g/kg). In pre-treatment groups,
animals received prazosin (0.2 mg/kg i.v), propranolol 0.5 mg/kg or combination of prazosin (0.2 mg/kg
i.v) and propranolol (0.5 mg/kg i.v) before i.v injection of cortisol (20 ?g/kg). Thereafter, blood samples
were collected for estimation of blood glucose level using the modified glucose oxidase method.
Cortisol caused significant increase in blood glucose level from 44.4±3.8 to 71.7±9.7 mg/dl. Pretreatment
of the toads with propranolol (0.5 mg/kg i.v) caused significant reduction (p? 0.01) in cortisolinduced
hyperglycaemia while pre-treatment with prazosin (0.2 mg/kg i.v) produced no significant effect
on hyperglycaemia induced by cortisol. The combination of both prazosin and propranolol completely
abolished the effects of cortisol on blood glucose level. The results suggest that cortisol-induced
hyperglycaemia in the toad (B. regularis) is mediated probably by both the ?- and ?-adrenergic
receptors with the beta adrenergic receptors playing dominant role.


Item Type: Journal article(non-copyrighted)
Format: PDF document,   325.2 KB
Copyright: Creative Commons LicenseCreative Commons license
Keywords: physiology
Department: Medicine and Surgery
Field of Study: Health and Society
Uploaded By: Uwaifo Ferdinand
Date Added: 06 Feb 2019 3:11pm
Last Modified: 06 Feb 2019
Journal URL: https://www.edouniversity.edu.ng/oer/journal/the_role_of_alpha_and_beta_adrenergic_receptors_in_cortisol-induced_hyperglycaemia_in_the_common_african_toad_bufo_regularis


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