[A case of acromegaly associated with variegated spinal disorders].

A case of acromegaly associated with variegated spinal disorders was reported. The spinal disorders were multiple cervical disc herniations, spinal epidural cavernous angioma, multiple ossification of the spinal ligament and lumbar canal stenosis. A 51-year-old woman with acromegaly, complaining of disturbances of delicate hand movement and gate, consulted our department. Her past history included diabetes mellitus, hypertension and progressing enlargement of her extremities. Serum growth hormone level was 65.7 ng/ml and somatomedin-c level was 746 ng/ml. Brain MRI showed a pituitary tumor extending to the right cavernous sinus. Cervical MRI revealed disc herniations at C5/6 and C6/7. Thoracic MRI revealed osteoporosis, ossification of the posterior longitudinal ligament and multiple ossification of yellow ligament. Lumbar MRI disclosed ossification of yellow ligament and canal stenosis. Anterior fusion of C5-C7 and an intracapsular removal of the pituitary tumor were performed. Its pathology was that of eosinophilic adenoma. After 3 months, she suffered from paraparesis. On repeating MRI examination with Gd-DTPA, a spinal epidural mass was found at T4. Under laminectomy of Th3-5 and Th8-11, the epidural mass and ossified yellow ligament were removed. The epidural mass was cavernous angioma. She was able to walk without any assistance. An association of spinal canal stenosis with acromegaly is well known. But the association of disc herniation and with the ossification of spinal ligaments is rather rare in the literature. Spinal epidural cavernous angioma is very rare. We discussed the etiological aspects and the management of spinal disorders with acromegaly.

The use of topographical constraints in receptor mapping: investigation of the topographical requirements of the tryptophan 30 residue for receptor binding of Asp-Tyr-D-Phe-Gly-Trp-(N-Me)Nle-Asp-Phe-NH2 (SNF 9007), a cholecystokinin (26-33) analogue that binds to both CCK-B and delta-opioid receptors.

The cholecystokinin (26-33) [CCK (26-33)] octapeptide analog Asp-Tyr-D-Phe-Gly-Trp(N-Me)-Nle-Asp-Phe-NH2 (SNF 9007) is a potent and selective ligand for both the CCK-B and delta-opioid receptors. Pharmacological studies of SNF 9007 suggest a relationship between the ligand requirements of CCK-B and delta-opioid receptors, which further implies a possible structural relationship between these receptors. We have utilized topographical constrainment of the important Trp30 residue to investigate structural features of SNF 9007 that would distinguish between binding requirements in this region for the CCK-B and delta-opioid receptors. Thus, the four optically pure isomers of beta-MeTrp were substituted for L-Trp30 of SNF 9007. Receptor binding results suggest that the preferred topography of the Trp30 residue for CCK-B receptor binding may be the 2S,3S (erythro-L) configuration whereas for the delta-opioid receptor it may be the 2S,3R (threo-L) configuration. Molecular modeling studies of these ligands further support the recently revised receptor-bound model for CCK-B octapeptide ligands (Kolodziej et al. J. Med. Chem. 1995, 38, 137-149) and are in good agreement with the DPDPE-delta opioid receptor "template" model (Nikiforovich et al. Biopolymers 1991, 31, 941-955).

[125I]SNF 8702: a selective radioligand for CCKB receptors.

The CCK-8 analogue, SNF 8702, was radioiodinated. [125I]SNF 8702 showed high-affinity specific binding for both guinea pig and mouse brain tissues, whereas no specific binding was seen for guinea pig pancreatic tissue. The properties of the site labeled by [125I]SNF 8702 were characterized by binding inhibition studies for a series of CCKA and CCKB receptor ligands. The binding selectivity profile corresponded to that for the CCKB receptor. The labeled compound is stable for more than 6 weeks during storage at -20 degrees C.

SNF9007: a novel analgesic that acts simultaneously at delta 1, delta 2 and mu opioid receptors.

Intracerebroventricular administration of the synthetic cholecystokinin analog SNF9007 (Asp-Tyr-D-Phe-Gly-Trp-[NMe]-Nle-Asp-Phe-NH2) produced antinociception in the mouse hot-plate and warm water tail-flick tests. The mechanisms of its analgesic actions were assessed by administering antagonists selective for CCK (cholecystokinin octapeptide, sulfated)-A and CCK-B receptors, as well as specific antagonists for the mu opioid receptor (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2, 1 microgram i.c.v.), the delta-1 opioid receptor [D-Ala2-Leu5,Cys6]enkephalin, 4.57 nmol i.c.v., 24 hr pretreatment), the delta-2 opioid receptor (naltrindole benzofuran, 25 pmol i.c.v.) and the kappa opioid receptor (nor-binaltorphimine, 10 mg/kg s.c.). The antinociceptive activity of SNF9007 was not a result of the activation of CCK receptors, as treatment with either CCK-A or CCK-B receptor antagonist was ineffective in blocking SNF9007 antinociception. Nor-binaltorphimine and naltrindole benzofuran were completely ineffective in blocking SNF9007 antinociception when administered alone or in combination. However, co-administration of delta-1 or delta-2 opioid receptor antagonists with the mu opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 resulted in a dramatic reduction in analgesic responses to SNF9007. Furthermore, the co-administration of mu+delta-1 + delta-2 opioid receptor antagonists resulted in an even greater inhibition of SNF9007 antinociception (> 10-fold shift). We conclude that SNF9007 acts simultaneously at brain delta-1, delta-2 and mu opioid receptors to induce antinociceptive effects in mice.

Characterization of SNF 9007, a novel cholecystokinin/opoid ligand in mouse ileum in vitro: evidence for involvement of cholecystokininA and cholecystokininB receptors in regulation of ion transport.

The effects of cholecystokinin (CCK) fragments and Asp-Tyr-D-Phe-Gly-Trp-[N-Me]Nle-Asp-Phe-NH2 1(SNF 9007), a synthetic CCK analog which binds with high affinity to CCKB and opioid delta receptors, were evaluated in isolated sheets of mouse ileum mounted in Ussing flux chambers. Serosal, but not mucosal, administration of cholecystokinin octapeptide-sulfated [CCK8(s)] and cholecystokinin tetrapeptide (30-33) [CCK4(30-33)] produced a brief, concentration-related increase in short circuit current (Isc) without changing tissue conductance. Serosal, but not mucosal, SNF 9007 produced a similar concentration-related increase in Isc which was followed by an immediate concentration-related and sustained decrease in Isc; no decrease in Isc was observed for either CCK8 or CCK4(30-33). The increase and subsequent decrease in the SNF 9007 Isc response were respectively classified as phase I (i.e., CCK-like) and phase II (opioid-like) activity. CCK8(s) and SNF 9007 (phase I) were active at low nanomolar concentrations, whereas CCK4(30-33) was active only at high nanomolar concentrations: the rank order of potencies to increase Isc was CCK8(s) > SNF 9007 > CCK4(30-33). Devazepide (L364,718), a selective antagonist of CCKA receptors, effectively blocked the action of CCK8(s), but not that of CCK4(30-33) or SNF 9007 (phase I). In contrast, 3R[+]-N-[2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-benzodiazepin-3-yl ]-N'- [3-methyl-phenyl]urea (L365,260), a selective CCKB receptor antagonist, blocked the action of CCK4(30-33) and SNF 9007 (phase I), and also antagonized CCK8(s), though to a lesser degree.(ABSTRACT TRUNCATED AT 250 WORDS)

Opioid receptor binding properties of analgesic analogues of cholecystokinin octapeptide.

Four analogues of cholecystokinin (CCK) octapeptide having analgesic activity after i.c.v. administration and high affinity for CCK-B receptors were studied for their ability to displace specific ligands, [3H]D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2. [3H][D-Pen2, 4'-Cl-Phe4,D-Pen5]enkephalin and [3H]U-69,593, for mu-, delta- and kappa-opioid receptors, respectively. None of the analogues tested have high affinity for either mu- or kappa-receptors (IC50 values greater than 0.7 microM), but their IC50 values for delta-receptors range from 29 to 1023 nM. The results suggest a relationship between the ligand requirements of CCK-B and delta-opioid receptors which further implies a possible structural relationship between these receptors.

A new, highly selective CCK-B receptor radioligand ([3H][N-methyl-Nle28,31]CCK26-33): evidence for CCK-B receptor heterogeneity.

[N-methyl-Nle28,31]CCK26-33 (SNF 8702) is a nonsulfated cholecystokinin octapeptide analog that is highly selective for cholecystokinin-B (CCK-B) receptors. Inhibition studies using [125I] Bolton-Hunter-labeled CCK-8 show that SNF 8702 has over 4,000-fold greater affinity for CCK receptors in guinea pig cortex relative to those in guinea pig pancreas. SNF 8702 was tritium-labeled to a specific activity of 23.7 Ci/mmol and its binding properties characterized for guinea pig brain membrane preparations. [3H]SNF 8702 binds to a single site with high affinity (Kd = 0.69-0.90 nM) in guinea pig cortex, cerebellum, hippocampus and pons-medulla. Of these four tissues, the highest receptor density was measured in the cortex (86 fmol/mg of protein) and the lowest in the pons-medulla (22 fmol/mg of protein). In contrast to findings of single-site binding in some brain regions, evidence for CCK-B receptor heterogeneity is observed under other conditions. [3H]SNF 8702 binding to membranes prepared from whole guinea pig brain shows biphasic association kinetics at a concentration of 2.0 nM consistent with the presence of binding site heterogeneity. Binding site heterogeneity is consistently observed for [3H]SNF 8702 binding to guinea pig whole brain membranes in saturation studies where a high-affinity site (Kd = 0.31 nM) is distinguished from a low-affinity site (Kd = 3.3 nM). Binding site heterogeneity is also observed for the midbrain-thalamic region. CCK-B receptor heterogeneity is suggested by the effect of the guanyl nucleotide analogue, guanylyl-imidodiphosphate (Gpp(NH)p), on [3H]SNF 8702 binding to CCK-B receptors in the cerebellum.(ABSTRACT TRUNCATED AT 250 WORDS)

Cyclic GMP accumulation by atriopeptins in cultured rat renal and vascular smooth muscle cells.

To evaluate the role of cyclic guanosine monophosphate (cGMP) in the vascular and renal action of atrial natriuretic peptide (ANP), we compared the effects of atriopeptins (APs) on cGMP accumulation in cultured cells from rat mesenteric vascular smooth muscle (VSM), glomerular mesangium (GM) and renal papillary collecting tubule (RPCT), and also evaluated the relationship between renal sodium or water excretion and urinary cGMP in AP-infused rats. Both AP I and AP III increased intracellular cGMP levels dose-dependently in all types of cells, while they did not affect intracellular cAMP levels or prostaglandin synthesis. AP III was 100 times more potent than AP I. The magnitude change in cGMP levels was largest in GM cells. The sensitivity of VSM and GM cells to AP III were greater than that of RPCT cells. There were significant positive relationships between urinary excretion of sodium or water and that of cGMP levels in AP-infused rats. These results may suggest that GM and VSM cells are the principal targets for ANP to stimulate cGMP synthesis and, possibly, to exert the renal sodium and water excretion, and also support the hypothesis that cGMP mediates the cellular action of ANP.

Synthesis and pharmacological evaluation of an 8 beta-bis(2-chloroethyl)amino opiate as a nonequilibrium opioid receptor probe.

8 beta-[Bis(2-chloroethyl)amino]-6,7-didehydro-3-hydroxy-17-methyl-4 ,5 alpha-epoxymorphinan (3) was synthesized from codeine, and its configuration at C-8 was determined by NMR. When evaluated in the guinea pig ileum and mouse vas deferens preparations, 3 was found to be a feeble, reversible agonist in both tissues without any irreversible agonist or antagonist activity. The fact that the 8 beta-bis-(2-hydroxyethyl)amino analogue was devoid of opioid activity suggests that steric hindrance to ligand-receptor association by a bulky 8-substituent may be responsible for this inactivity.

Studies on synthesis and relationship between analgesic activity and receptor affinity for 3-methyl fentanyl derivatives.

In the present paper, the synthesis and analgesic activity (mice, i.p. hot plate test) of the derivatives of 3-methyl fentanyl are briefly described. Compound 7302, cis-N-[1-(2-hydroxy-2-phenylethyl)-3-methyl-4-piperidyl]-N-phenylpropionamide (cis: 3-methyl/4-N-phenylpropionamide) is found to be the most potent analgesic agent in this series synthesized by our laboratory (ED50 = 0.0022 mg/kg). The analgesic activity of 7302 is 28 times more potent than that of fentanyl and 6300 times more than that of morphine. The partition coefficients of 10 compounds in the series are determined by high performance liquid chromatography (HPLC) and their log p values are about 3. There are no regular relationships between the analgesic activity and partition coefficients. Study on the specific binding of 8 out of the above 10 compounds to crude synaptic plasma membrane (P2-fraction) of mouse brain demonstrates that there is an excellent statistical linear correlation (r = 0.998) between the analgesic potency and the specific binding affinity. The result shows that the analgesic potency of the derivatives of this series is mainly dependent on binding affinity for opiate receptor.