Immunocytochemical localization of luteinizing hormone-releasing hormone (LHRH) in Vibratome-sectioned brain.

Immunocytochemical localization of neuropeptides such as luteinizing hormone-releasing hormone (LHRH) is generally performed on Bouin's fixed tissue sections, following tissue dehydration in alcohols and embedment in paraffin. When the final reaction product accurately reflects content and distribution of the neuropeptide has not been examined carefully. Our data indicate a decrease in radioimmunoassayable LHRH content of brain fixed in Bouin's solution and a further significant reduction following dehydration with alcohol. In order to circumvent this loss of hormone, sections of fixed brain were cut on a Vibratome at 30 micron and collected in phosphate-saline buffer. These Vibratome sections revealed a significantly greater amount of overall immunoreactivity and fiber distribution as compared to paraffin-embedded sectioned tissue. These results suggest that certain neuropeptides, soluble in alcohol, can be extracted during dehydration processes necessary for paraffin embedment.