Cell lines

Primary human fetal mixed glial/neuronal brain cell, human microglial cell

Preparation method

The solubility of this compound in DMSO is >30.6 mg/mL. General tips for obtaining a higher concentration: Please warm the tube at 37 ℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20℃ for several months.

Reacting condition

0.1 nM

Applications

In mixed glial/neuronal cell cultures infected with HIV-1, endomorphin-1 potentiated the expression of HIV-1 in a bell-shaped dose-response manner. Endomorphin-1 (0.1 nM) consistently amplified the replication of HIV-1. In microglial cells, endomorphin-1 potentiated the expression of HIV-1, with maximal enhancement of HIV-1 expression at 10-10M.

Animal models

Male ICR mice, adult female Sprague–Dawley rats

Dosage form

i.c.v. injection, 5 min, 3.28 nM-16.38 nM, intrathecal injection

Application

Endomorphin-1 inhibited the tail-flick (AD50 = 6.16 nM) and hot-plate responses (AD50 = 1.94 nM) in a dose-dependent manner at 5 min after i.c.v. injection. In rats, intrathecal injection of 1:10 and 1:100 times diluted EM1 antiserum significantly decreased the effect of 2 Hz electroacupuncture analgesia.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

Endomorphins are two endogenous opioid peptides. Endomorphin-1 (Tyr-Pro-Trp-Phe-NH₂) and endomorphin-2 (Tyr-Pro-Phe-Phe-NH₂) are tetrapeptides with the highest known affinity and specificity for the μ opioid receptor. Endomorphin-1 is located in the nucleus of the solitary tract, the periventricular hypothalamus, and the dorsomedial hypothalamus, where it is found within histaminergic neurons and may regulate sedative and arousal behaviors¹. It is assumed that endomorphins are the cleavage products of a larger precursor, but this polypeptide or protein has not yet been identified. Perikarya expressing EM2-like immunoreactivity were present in the posterior hypothalamus, whereas those expressing EM1-like immunoreactivity were present in both the posterior hypothalamus and the nucleus of the solitary tract (NTS). EM1-like immunoreactivity was more widely and densely distributed throughout the brain than was EM2-like immunoreactivity, whereas EM2-like immunoreactivity was more prevalent in the spinal cord than was EM1-like immunoreactivity. endomorphins participate in modulating nociceptive and autonomic nervous system processes and responsiveness to stress.

References:
1. Greco, MA; Fuller, PM; Jhou, TC; Martin-Schild, S; Zadina, JE; Hu, Z; Shiromani, P; Lu, J (2008). "Opioidergic projections to sleep-active neurons in the ventrolateral preoptic nucleus". Brain Research 1245: 96–107.