Intraventricular somatostatin-14, arginine vasopressin, and oxytocin: analgesic effect in a patient with intractable cancer pain

The analgesic effect of intraventricular somatostatin-14 (SOM-14), arginine vasopressin (AVP), and oxytocin (OT) were tested in one terminally ill cancer patient with a diffuse mesothelioma suffering intractable continuous and incapacitating thoracic pain. SOM-14 reduced pain by 90% for 48 min; AVP reduced pain by 95% for 75 min, and OT reduced pain by 88% for 77 min. The only notable side effects were seen after the administration of AVP, which induced anesthesia and flaccid paralysis of the lower limbs, from which the patient fully recovered after 20 h.     

Vasopressinergic,Oxytocinergic, and Somatostatinergic Neuronal Activity after Adrenalectomy and Immobilization Stress

Twenty days after bilateral adrenalectomy (ADX) or immediately after the last of three 6-h long immobilization periods, the levels of hypothalamic and neurohypophyseal L-[³⁵S]Cys-labeled arginine vasopressin (AVP), oxytocin (OT), and somatostatin-14 (SRIF) (only stressed animals) were measured simultaneously in male Wistar rats, after third ventricular administration of the labeled precursor, via guide-cannulae. The acetic acid-extracted labeled peptide fractions were purified by two sequential HPLC steps. After a 4 h period of labeling, only L-[³⁵S]Cys-AVP was selectively increased in the hypothalami of ADX-ized rats, compared to the sham-operated animals, possibly reflecting a significant activation of the paraventricular parvocellular (PVC) AVP/corticotropin-releasing factor (CRF) neurons. The increased accumulation of neurohypophyseal L-[³⁵S]Cys-labeled AVP and OT in these animals, without changes in the endogenous levels of these peptides, as measured by UV absorbance, also suggests a moderate activation of the magnocellular (MGC) AVP and OT neurons, as a consequence of adrenal insufficiency. In response to immobilization stress, levels of L-[³⁵S]Cys-OT were selectively increased in the hypothalami and corresponding neurohypophyses, 2 h and 4 h after receiving the label, concomitantly with a statistically significant reduction in the stores of OT in the neural lobes. AVP and SRJF biosynthesis remained unaffected by immobilization; the neurohypophyseal AVP stores likewise remained unchanged. These observations suggest the selective activation of MGC-OT neurons in response to chronic immobilization stress. Selective increases in hypothalamic L-[³⁵S]Cys-AVP in ADX-ized rats, and in hypothalamic L-[³⁵S]Cys-OT in chronically stress-immobilized rats, are presented as a measure of PVC-AVP/CRF and MGC-OT neuronal activation, respectively.     

New approach for graded compression spinal cord injuries in Rhesus macaque: method feasibility and preliminary observations

Background Current models of spinal cord injury (SCI) have been ineffective for translational research. Primate blunt SCI, which more closely resembles human injury, could be a promising model to fill this gap. Methods Graded compression SCI was produced by inflating at T9 an epidural balloon as a function of spinal canal dimensions in a non‐uniform group of monkeys. Results Sham injury and cord compression by canal invasion of 50–75% produced minimal morpho‐functional alterations, if at all. Canal invasion of 90–100% resulted in proportional functional deficits. Unexpectedly, these animals showed spontaneous gradual recovery over a 12‐week period achieving quadruped walking, although with persistent absence of foot grasping reflex. Histopathology revealed predominance of central cord damage that correlated with functional status. Conclusions Our preliminary results suggest that this model could potentially be a useful addition to translational work, but requires further validation by including animals with permanent injuries and expansion of replicates.