Background and object: The objective of this study was to determine the effect of a very low dose protirelin in cerebrospinal fluid (CSF) glucose, magnesium and lactate levels after spinal cord trauma (SCT) in rabbits. We also aimed to evaluate whether this very low dose might induce analeptic effect.
Material and methods: Twenty rabbits were divided equally into two groups: group I (n=10) was the control group, suffered from SCT but received only saline after SCT. Group II (n=10) (treatment group), received a very low dose of 0.05 mg/kg thyrotropin releasing hormone (TRH), analogue protirelin intratechally after SCT. The basal CSF glucose, magnesium and lactate levels were recorded in both groups. CSF lactate, glucose and magnesium contents were recorded at the same time (an hour before and after) SCT. Serum thyroid stimulating hormone (TSH), freetriiodothyronine (FT3) and freethyroxine (FT4) were measured in all rabbits before and after SCT.
Results: Before spinal cord trauma, there were not any significant differences in glucose, lactate and magnesium levels between group I and II whereas, after spinal cord trauma in group II, the significant suppression in elevation of lactate and glucose depletion (p<0.05) were observed while no significant suppression was observed in magnesium level (p>0.05) as compared with group I (Table 3). In respect of serum TSH levels, there were not any significant differences between two groups before and after SCT.
Conclusions: This study showed that intratechal TRH has no analeptic effect on serum TSH, FT3 and FT4 levels but can attenuate the increase of lactate levels following spinal cord trauma. No significant decrease in magnesium level and also suppression of glucose decline in group II, may be related to the neuroprotective effects of TRH.