The Regulation Of Calorie Restriction On The Expression Of Voltage-dependent Calcium Channel In Rat Hypothalamus And Pituitary

Objective: Moderate restriction of food intake, referred to as calorie restriction (CR), has been found to retard aging process and prolong lifespan in laboratory animals, including lower organisms and mammals such as drosophila, worm and rodents. Aging is closely related with the disturbances of some neuro-endocrinous processes. And as the most important endosecretory organs, hypothalamus and pituitary secret many kinds of hormones which plays pivotal roles to the life span, as well as the function of the other secretory organs. Voltage-dependent calcium channels (VDCCs), the well-known modulating ion channels, also regarded as a factor to modulate the secretion or transmission of hormones. Thus, to further study the relationship between the VDCCs and endocrine system during CR, we explored the expression of five different VDCCs in hypothalamus and pituitary of rats from CR or Ad libitum (AL) feeding groups. Methods: Rats are grouped randomly as CR and AL, Rats in the CR group are given the individual allotments of food contained 60% of the food ingested daily by each rat during the next 8 months. Before the gene and protein test, we measure the SOD activity and MDA level in serum besides their body weight in the two groups. Subsequently, using real time RT-PCR, western blotting and immunochemistry, we detect the expression of interested Ca2+ channels, including L-, N-, P/Q-, R-and T-type channels in hypothalamus and pituitary. Results: After 8 months'food intervention, body weight and MDA level of rats in CR group decreased markedly as compared to AL group, while SOD level is statistically insignificant. In addition, it seems that the expression of the examined Ca2+ channels in hypothalamus and pituitary have a tendency to decrease, although the significant statistic difference are only observed in N- and R-type or N-, T-and R-type channels respectively in hypothalamus or pituitary. Conclusion: In the long-term calorie restriction, hormones related with energy metabolism show different changes. And those changes are closely related to the hormone-mediated modulation of five different voltage-dependent calcium channels, which is shown as the results of RT-PCR, western blotting and immunochemistry.