Pakistan Journal of Pharmaceutical Sciences Vol.18, No.3, July 2005, pp.42-45 THE EFFECTS OF ACETYLSALICYLIC ACID ON THE PITUITARY PROLACTIN OF THE LIZARD, UROMASTIX HARDWICKII MAHMOOD AHMAD, RUQAIYA HASAN, MANSOOR AHMAD*,ANILA QURESHI* AND SHAMA MASROOR Department of Physiology, University of Karachi, Karachi-75270, Pakistan *Department of Physiology, New York Medical College, and Westchester Hospital, Valhalla, New York, U.S.A. This study deals with the intravenous administration of 7mg acetylsalicylic acid (ASA) solution to Uromastix hardwickii for 4 days. It enhances the activity of anterior pituitary lactotrophs, when 0.1 ml of pituitary homogenate of ASA treated was injected hypodermically to crop- sac showed a greater diametric response and increased activity with milk like secretion than that of the injections of 0.1 ml homogenate of control pituitary. The present study indicated that ASA induces hyperprolactinemia. Keywords: Acetylsalicylic acid, Uromastix pituitary, lactotrophs INTRODUCTION Aspirin (acetylsalicylic acid, ASA) is the best known and extensively prescribed salicylate. It is an analgesic, antipyretic and anti-inflammatory agent belongs to non steroid anti-inflammatory drug class (NSAIDs) (Kacso and Terezhalmy, 1994). In larger doses ASA produce measurable anti-inflammatory changes in patients suffering from rheumatoid arthritis (Boardman and Hart , 1967; Deodhar et al., 1973 and Botting, 1999) ASA is the classical anti thrombotic agent and is widely used for its anti platelet activity (Mueller, 2004 and Niv et al., 2005). NSAIDs have multiple pharmacological effects with multiple mechanisms of actions. In both, animals and man large doses of Salicylates cause hyperglycemia and glycosuria, through depletion of liver and muscle glycogen (Randall, 1963; Mitzkat and Schonhofer, 1978). High doses of salicylates activate central sympathetic centers and cause release of epinephrine from the adrenal medulla; though this release is partially responsible for the hyperglycemia and depletion of liver glycogen. On the other hand steroid secretion is stimulated by adrenal cortex through their effect on the hypothalamus and increase transiently the plasma concentrations of free adrenocorticoids by displacement from plasma proteins (Paulus and Whitehouse, 1973). ASA exhibits many side effects and manifest the toxic actions on gastric mucosa and kidney. Chronic use of ASA in managing inflammatory disorders are associated with a high prevalence of gastric and duodenal ulceration (Smith et al., 2000 and Niv et al., 2005). ASA directly or indirectly influences the endocrine system. It reduces the plasma levels of thyroid stimulating hormone (TSH), triiodothyronine (T3) and thyroxine (T4) in human (Langer et al., 1978). In mammals it elevates prolactin (PRL) levels (Luigi et al., 2001 and Ahmad et al., 2005) and reduces cortisol response (Cavagnini et al., 1979). In the present investigation ASA was administered intravenously to Uromastix hardwickii and its role to initiate prolactin secretion through hypophyseal system was determined by a crop-sac receptors response. MATERIALS AND METHODS Assay animals In all twenty four Uromastix hardwickii were used in this study to investigate the effects of acetylsalicylic acid on pituitaries. The lizards were obtained from local suppliers and were kept in the laboratory at a constant room temperature of 29+1 o C (Ahmad and Taqawi, 1978a, b, 1979 and Ahmad et al., 1980). Twenty four pigeons aging 8-10 week, belonging to white race were used for crop-sac assay. The birds were obtained from local breeders and housed in the laboratory for 5 days; keeping one pigeon in one cage. They were fed with millet and water ad libidum (Ahmad et al., 2001a, b and 2002a). Drug information Aspirin was a name first used in the late nineteenth century for acetylsalicylic acid (ASA). The first pharmacological data on aspirin appeared in 1899. At present, aspirin is probably used more widely and in larger quantity than any other therapeutic agent. Salicylates are most commonly used as antipyretic and analgesic agent in the relief of headaches, of minor aches and pains. But the most important use is in the treatment of arthritis and rheumatic fever (Donald, 1992).