Table 5.

Analysis of R subunits in salivary glands identified by photoaffinity labelling

	SMG		Parotid
R subunits	Control	Diabetic	Control	Diabetic
RII (50–55 kDa)	<5	<5	123.23	150
RI (45–49 kDa)	186.28	102.2	15.10	9.4
Rfr (20–40 kDa)	203.08	63.10	<5	<5
Rfr (15–19 kDa)	103.31	38.18	0	0
Rfr (<15 kDa)	66.37	0	0	0

Measurement of relative densities of the individual bands on a representative autoradiogram was carried out using NIH Image. Data shown are from one of three consecutive experiments with the same findings. SMG showed no photoaffinity labelled cyclic AMP binding protein migrating with the mobility of RII. Conversely, parotid had only trace amounts of photoaffinity labelled cyclic AMP binding protein with the relative mobility of RI. Note: Photoaffinity labelling shows only proteins that have a covalently bound cyclic AMP analogue; therefore, the faster moving components are R subunit fragments.