Actividad de la 6-fosfofructo-2-quinasa y contenido de fructosa-2.6-bifosfato en glándulas parotidas de ratas despues del tratamiento con isoproterenol / Activity of 6-phosphofructo-2-quinase (PFK-2) and contents of fructose-2.6-biphosphate in parotid glands of the rats after treatment of isoproterenol

La sialadenosis en animales de laboratorio puede ser provocada por la administración de un agonista betadrenérgico conocido como isoproterenol. Su efecto produce hipertrofia e hiperplasia de las glándulas salivales, especialmente de la glándula parótida. La 6-fosfofructo-2-quinasa (PKF-2) es una enzima bifuncional que cataliza tanto la síntesis como la degradación de la fructosa-2,6-difosfato. este metabolito es un potente activador de la 6-fosfofructo-1-quinasa (PKF-1) enzima clave en el proceso glucolítico. En este trabajo determinamos la actividad de la PKF-2 y el contenido de fructosa-2,6-bifosfato en glándulas parótidas de ratas, al ser estimuladas con varias dosis de isoproterenol

Effects of prolactin and androgens on enzymes of carbohydrate metabolism in prostate of castrated bonnet monkeys Macaca radiata (Geoffroy).

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combinations of these androgens with PRL/Br on the specific activities of caudal and cranial prostatic cellular enzymes involved in carbohydrate metabolism in castrated mature bonnet monkeys have been studied. Castration decreased all the enzymes studied such as hexokinase (HK), 6-phosphofructokinase (6-PFK), glyceraldehyde-3-phosphate dehydrogenase (G-3-PD), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G-6-PD) and 6-phosphogluconate dehydrogenase (6-PGD) in the cranial and caudal prostates. PRL elevated the activities of all the enzymes above normal except G-3-PD of cranial lobe. In the caudal lobe, PRL brought back the activities of HK, PFK, PK, G-6-PD to normal and 6-PGD above normal except G-3-PD. TP/DHT treatment increased all the enzymes in both the lobes. PRL given along with TP/DHT further enhanced the androgen action with regard to HK, PK, G-6-PD and 6-PGD of cranial and PFK, G-3-PD, PK, G-6-PD and 6-PGD of caudal lobe. Br treatment did not produce any alteration of these enzymes in both the lobes. In the cranial lobe, during Br+TP/DHT treatment, the stimulating effects of androgen were unaffected on all the enzymes except PK. On the other hand in the caudal, the stimulatory effects of androgens were affected and the activities of HK, PFK, PK and 6-PGD were significantly decreased. The present results suggest that PRL has a direct as well as a synergistic action with androgens on enzymes of EMP and HMP shunt in the prostates of monkeys.