Substance P in human hypothalamus.
The undecapeptide substance P (SP) is found in widely dispersed areas of the brain. Recently, in experimental animals, a role for SP as a presumptive neuromodulator of endocrine responses has been described. Part of this role appears to be expressed at the level of the hypothalamo-pituitary axis. The distribution of SP in human hypothalamus and pituitary stalk has rarely been examined. In this study the distribution of SP was determined using radio-immunoassay and immunohistochemical methods in 7 regions of hypothalamus and the pituitary stalk in 21 autopsy samples. The SP content was greatest in the pituitary stalk (16.7 +/- 2.9 ng/mg protein) and the mediobasal hypothalamus at the level of the tuber cinereum. (8.3 +/- 1.1 ng/mg protein) compared with all other regions (range 3.7 to 6.0 ng/mg protein). Histochemical studies in 7 cases showed a dense innervation of the pituitary stalk portal vessels by substance P-containing nerve terminals. The pituitary stalk, mediobasal and lateral hypothalamus had the highest number of SP-containing neuronal perikarya. The SP content was not affected by age, sex or delay from death to freezing of tissue. The distribution of SP supports the view that the peptide is a neuromodulator of hypothalamo-pituitary endocrine function in man.
D000328:Adult; D000368:Aged; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D007120:Immunochemistry; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism; D009994:Osmolar Concentration; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism; D013373:Substance P / Q000378:metabolism*
D013373:Substance P