ABSTRACT
Background: The menstrual cycle is the result of complex interacting processes within the hypothalamus, the hypophysis, the ovaries and the uterus. Patterns of change in plasma concentrations of various minerals have been the subject of several research endeavours. Therefore, the present study has been conducted to study and compare the serum calcium, magnesium and its ratio in menopausal and reproductive age group. Methods: The study was performed in two groups of subjects with a control group of 30 healthy women of reproductive age group and a postmenopausal group of 30 women with varying durations of menopause (less than and more than 10 years after menopause). Three blood samples were obtained from the control group –one each in early follicular phase, ovulatory phase and during luteal phase for estimation of calcium and magnesium. One sample was taken from the menopausal age group for the estimation of calcium and magnesium using commercially available kit. The values are expressed as mean ± S.D. The comparison between the different phases of menstrual cycle in reproductive age group with menopausal women was performed using student t-test. P value less than 0.05 was considered significant. Result: The serum Ca2+, Mg2+ and Calcium/ Magnesium ratio was found to be statistically insignificant (p=1.00), during different phases of menstrual cycle in normal cycling women is statistically insignificant. Discussion: The cyclical changes of serum Ca2+ and Serum Mg2+ levels in women of reproductive age may be due to the cyclical changes in the level of sex hormones during different phases of menstrual cycle
ABSTRACT
BACKGROUND: Central sensitization of neuropathic pain is associated with an influx of extracellular calcium via the opening of N-methyl-D-aspartate (NMDA) receptor-gated ion channels, which is usually blocked by a magnesium plug. Many studies have found that intrathecal or intraperitoneal magnesium suppress neuropathic pain. Therefore, it is possible that serum and cerebrospinal fluid Ca2+, Mg2+, and Ca2+/Mg2+ ratio are changed in neuropathic pain. The purpose of this study was evaluated changes in serum and cerebrospinal fluid Ca2+, Mg2+, and Ca2+/Mg2+ ratio in neuropathic rats. METHODS: Male Sprague-Dawley rats were prepared with tight ligation of the left lumbar 5th and 6th spinal nerves to produce neuropathic pain. The threshold of mechanical allodynia was evaluated by the up-down method using withdrawal response to a von Frey filaments stimulus on the 3rd, 7th, and 14th day. Rats with a threshold of less than 4 gram were selected as the experimental group. On the 16th day, serum and cerebrospinal fluid Ca2+, Mg2+, and Ca2+/Mg2+ ratio were measured. Experimental group data were then compared with those of an unoperated control group and an unligated sham group; each group contained 10 animals. RESULTS: No statistic differences were found between groups. CONCLUSIONS: Our results suggest that serum and cerebrospinal fluid Ca2+, Mg2+, and Ca2+/Mg2+ ratio in neuropathic rats do not differ from those of normal rats because of physiologic homeostasis is maintained by active transport through the blood-brain-barrier despite of activation of NMDA receptor-gated ion channels. However, we believe that the Mg2+ ion-dependent voltage-gating in rats with neuropathic pain may be deficient in a chronic condition due to a decreased Mg2+ binding affinity of the NMDA receptor-gated channel, as has been found in hippocampal granule cells in epileptic rats.