Somatostatin receptors and disease: Role of receptor subtypes

摘要: A variety of human neuroendocrine tumours express SSTR. The five recently cloned SSTR subtypes have a distinct chromosomal localization and pharmacological profile, tissue-specific expression pattern which suggests differential function in different organ systems. Most carrying may multiple subtypes, while the SSTR2 subtype is most predominantly expressed. somatostatin analogue, octreotide, binds with high affinity to SSTR5 low SSTR3 subtype. This analogue does not bind SSTR1 SSTR4 subtypes. No major differences binding characteristics been found between octreotide two other clinically used octapeptide SST-analogues, BIM-23014 RC-160. Our preliminary data indicate that an absent hormonal response vitro also implies proposed be related clinical beneficial effect treatment, functional significance clear at present. In addition it unclear subtype(s) involved antimitotic actions SST(-analogues). Further developments regard oncological application SST analogues await identification mediating anti-proliferative effects, as well development selectively activate this subtype(s). good correlation has presence mRNA [125I-Tyr3]octreotide primary tumours. Therefore, scintigraphy their metastases presumably visualizes SSTR2-expressing tumours, although reasonable assume SSTR5, lesser extent SSTR3, when expressed simultaneously SSTR2, contribute visualization