Table 1

Characteristics of the antisera used in RIAs

PeptideAntibodyRegional specificityTiterSensitivity, fmol/tubeImmunoreactivity specificityRef.
CCKCCK-2C terminal tyr-SO41:28,0000.2CCKs with sulfated tyrosine, no gastrins10
CCKO2C terminal1:250,0000.1All forms of CCK and gastrin10
CGRPD11N terminal1:80,0000.6No cross reaction with IAPP11
GastrinGas179C terminal1:200,0000.2All forms of gastrin12
GIPSpec 19C terminal1:24,0001.2Highly specific12
GlucagonGL77Mid to N terminal1:4,0000.4Cross reacts with glicentin12
GlucagonmonoMid to N terminal1:70,0000.3Cross reacts with glicentin12
GlucagonRCS5C terminal1:200,0000.2Pancreatic glucagon specific12
InsulinM8309Unknown1:1,000,0000.4No cross reaction with IGF-I or IGF-II13
MotilinM1N terminal1:200,0001.0Recognizes porcine and human motilin12
MotilinRAS7160C terminal1:150,0000.5Recognizes rat, dog, and porcine motilin12
NeurotensinNT58C terminal1:100,0000.2No cross reaction with NT1–814
NPYYN7N terminal1:120,0001.5No cross reaction with PYY or PP15
Peptide YYY21N terminal1:80,0000.4No cross reaction with NPY or PP16
Peptide YYY24C terminal1:100,0000.5No cross reaction with NPY or PP16
PPHPP3Unknown1:250,0000.2No cross reaction with PYY or NPY12
SecretinSc10Mid to C terminal1:200,0000.2Highly specific10
SomatostatinK9Ring structure1:40,0000.3Cross reacts with 14 and 28 AA forms12
Substance PSPG1N terminal1:80,0000.5Highly specific12
VIPV9C terminal1:320,0000.3Highly specific12
  • We assayed python plasma and tissues for GI peptides by means of antibodies (column 2) to mammalian peptides (column 1).